Method of lining smelting furnaces



Oct. 10, 1939. .1. A. HESKETT METHOD OF LINING SMELT ING FURNACES Filed Jan. :5, 1938 \NVENTCR J HN A. HESKETT BY v ATTYS.

Patented Oct. 10, 1939 UNITED STATES PATENT OFFICE IHETHOD 0F LINLNG SMELTING FURNA CES John Ambrose'Heskett, Huntly, Auckland,

Zealand New Application 3, 1938,-Serial No. 183,197 In New Zealand January 27, 1937 3Claims.

It has been common practice to line these furnaces with a refractory material, but considerable trouble occurs owing to the fluxing influences of the materials being melted, destroying the said lining. This is especially the case in respect of reverberatory furnace walls and roofs where the dust from the fuel or from the materials being melted, comes in contact therewith.

It has been common practice also to water cool the refractory linings by means of water coils or water jackets having water passed through or over them, but such causes the brick lining to be preserved only for a somewhat longer period.

2 a with the method whereby the furnace is provided with its lining forming the subject of the present invention, a lining is formed of a ma terial approximating in its physical properties to the material for the melting of which the furnace is used, so that a protective surfacing of a permanent character is provided that will withstand the fluxing influence that would take place in normal circumstances in both open hearth and reverberatory furnaces.

35 The invention consists in a construction of furnace having cooling means associated therewith in which a lining or coating for the walls and roof thereof is formed by causing molten material of the same nature as that for which so the furnace is intended to be used, to be'distributed or spread over the surfaces of the walls and roof and rapidly cooled to a chilled condition. This then forms a heavy coat of the solid slag which retains its adhesiveness to the said 45 surfaces and maintains its physical separation from the material being dealt with in the furnace, and such coating will serve to form aninsulating and wear resisting lining for such surfaces. The said cooling means associated with 50 the furnace are designed to encircle the walls and roof thereof with water cooled coils or jackets in any of the ways already known so that the internal surfaces are cooled and kept cool in order to chill the molten material as it is spread 55 or thrown on such surfaces to coat them. and to then maintain the coating thus formed as the furnace continues its operations.

The thickness of the lining or coating may be varied to suit any special circumstances, but

where a thick lining of the slag material is re- 5 quired, the furnace surfaces may be provided'with means for effecting a. key hold upon the material spread thereon, as such material is chilled and solidifies. For this purpose. such means may suitably consist of studs of any approved metal, 9 as iron or steel, of suitable diameter and length, that are welded or screwed or otherwise aflixed to the metal shell of the furnace so asto project inwardly for a desired distance. ,These are distributed over such surfaces at the requisite distances apart to effectually cover the area thereof. In addition to providing for the keying of a. thicker lining, the presence of these metal studs ensures of a more rapid cooling of the slag material spread on the surfaces. Also by reason of 20 the presence of these studs in association with the lining, the lining is made less susceptible to the action of contraction and expansion on the cooling and heating of the furnace so that these operations may be effected more rapidly without fracturing the lining.

The thickness of the applied lining may be increased by using longer studs and spacing them apart at closer intervals. A desired thickness of lining may be arrived at by either increasing or decreasing the rate at which the molten materialv is applied.

The said material may be suitably applied to the furnace surfaces by distributing it thereon by a method in which the molten material is splashed over the surfaces by means of jets of compressed air, steam or other gases introduced into the mass. or when it is to be applied to a rotating furnace, it may be spread over its surfaces by centrifugal action brought about by the 4 rotations.

It has been found that a furnace having a lining formed by the material and applied in the manner herein described is practically indestructible and requires little or no attention when cooled down, to put it in order for further smelting operations.

A suitable manner of giving effect to the inven tion is illustrated in the accompanying drawing, in which: 1

Figure 1 is a sectional plan of a furnace, as lined in accordance herewith, and showing the furnace wall formed or provided with the aforesaid studs for keying the lining material thereto.

Fig. 2 is a longitudinal sectional elevation of 55 the furnace but with its wall made without the studs, and unlined.

Fig. 3 is an enlarged sectional detail of a portion of the furnace wall, as provided with the keying studs. i

Fig. 4 is a cross-sectional elevation of the furnace shown in Fig. 2.

The said furnace comprises a horizontal cylindrical furnace chamber A of metal, opening at one end into a flue B and at the other having means whereby blast fuel may be led .into the chamber, as for instance the coal dust duct C and the air blast nozzle D shown in the drawings. The furnace is provided with any approved means for cooling its wall. In the drawing, the means shown consist in a water spray pipe E arranged to extend along above the furnace length and operating to spray the external surface area with cold water. Also, the furnace chamber is provided with a hearth F of suitable refractory material. In addition, the internal surface of the furnace wall may be made or provided with a number of metallic studs G distributed over its area, these being varied in size and length and in spaced relationship over the area in the manner hereinbefore described.

Provision is made in the sides of the furnace wall for the insertion of blower pipes for the admission of the compressed air or steam used for the spraying of the lining material onto the internal surface. Such provision consists in a number of tuyre-like openings H disposed at intervals along each side of the furnace, the blower pipes being shown in Fig. 4 and represented at J.

In Figs. 2 and 4, the furnace is shown with a quantity of the molten slag material K covering the hearth F and ready for distribution over 7 the furnace wall under the action of the air or steam jets introduced through the blower pipes J.

I claim:

. such surfaces are 1. A reverberatory furnace for the smelting of phosphate rock, silicious limestone, or other like basic materials, and having means for cooling its internal surfaces associated therewith, in which coated with a coating of the material being smelted, applied thereto by a method under which a quantity of the material in a molten state, contained within the furnace, is caused to be splashed over the surfaces by means of jets of compressed air, steam or other gases directed into the molten mass, and is then rapidly cooled by the cooling of the surfaces to which it is applied.

2. A method of lining the surfaces of a reverberatory furnace for the smelting of phosphate rock, silicious limestone or other like basic materials. having means for cooling its internal surfaces consisting in splashing such surfaces with the material for which the furnace is used by means of jets of compressed air, steam or other gases directed into a mass of such material in a molten condition contained within the furnace, and then rapidly cooling such surfaces.

3. A reverberatory furnace for the smelting of phosphate rock, silicious limestone, or other like basic materials, and having means for cooling its internal; surfaces associated therewith, in which such surfaces are coated with a coating of the material beingsmelted, applied thereto by a method under which a quantity of the material in a molten state, contained within the furnace, is caused to be splashed over the surfaces by means of jets of compressed air, steam, or other gases directed into the molten mass, and is then rapidly cooled by the cooling of the surfaces to which it is applied aand means for keying such coating to the surfaces comprising inwardly extending metal studs ailixed to the surfaces and disposed at intervals apart over their area.

' JOHN AMBROSE HESKETT. 

